Gas-operated revolver cannon with
four chambers. These guns are fitted with triple-coil muzzle velocity
gauge and fuze-setter for use with Advanced Hit Efficiency And Destruction
(AHEAD) projectiles. The first two coils are located 3.9 inches (10
cm) apart and measure the exact projectile velocity. This is then
used to calculate the fuze setting so as to achieve the proper flight time.
The third coil then imparts this data to the fuze via a electro-induction
system. The fuze itself is a high-precision timer which detonates
the expelling charge at a given distance in front of the target.

Lockheed Martin has become the U.S.
licensee to Oerlikon Contraves for sale and manufacture of the gun systems.
The USN performed evaluation testing of this weapon system in 2005, but
has decided not to purchase.

On Danish vessels these guns will be
controlled by the SaabTech CEROS fire control systems and the Terma Command
Management System of the CSS.

The "1000" in the designation is a reference
to the rate of fire. The actual gun barrel length is about
79 calibers.